PIC16F914-I/PT Microchip Technology, PIC16F914-I/PT Datasheet - Page 42

• Manufacturer Part Number: PIC16F914-I/PT
• Description: IC PIC MCU FLASH 4KX14 44TQFP
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F914-I/PT

• Program Memory Type: FLASH
• Program Memory Size: 7KB (4K x 14)
• Package / Case: 44-TQFP, 44-VQFP
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LCD, POR, PWM, WDT
• Number Of I /o: 35
• Eeprom Size: 256 x 8
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 2 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: PIC16F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 256 B
• Interface Type: SSP/I2C/AUSART/SPI
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 35
• Number Of Timers: 3
• Operating Supply Voltage: 2 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120, ICE2000, DV164120, DM163029
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 8-ch x 10-bit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: XLT44PT3 - SOCKET TRAN ICE 44MQFP/TQFPAC164305 - MODULE SKT FOR PM3 44TQFP444-1001 - DEMO BOARD FOR PICMICRO MCUAC164020 - MODULE SKT PROMATEII 44TQFP
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

PIC16F91X
3.5.2
The Oscillator Start-up Time-out Status (OSTS) bit
(OSCCON<3>) indicates whether the system clock is
running from the external clock source, as defined by
the FOSC bits, or from the internal clock source. In
particular, OSTS indicates that the Oscillator Start-up
Timer (OST) has timed out for LP, XT or HS modes.
3.6
Two-Speed Start-up mode provides additional power
savings by minimizing the latency between external
oscillator start-up and code execution. In applications
that make heavy use of the Sleep mode, Two-Speed
Start-up will remove the external oscillator start-up
time from the time spent awake and can reduce the
overall power consumption of the device.
This mode allows the application to wake-up from
Sleep, perform a few instructions using the INTOSC
as the clock source and go back to Sleep without
waiting for the primary oscillator to become stable.
When the PIC16F91X is configured for LP, XT or HS
modes, the Oscillator Start-up Timer (OST) is enabled
(see
(OST)”). The OST timer will suspend program
execution
Two-Speed Start-up mode minimizes the delay in code
execution by operating from the internal oscillator as
the OST is counting. When the OST count reaches
1024 and the OSTS bit (OSCCON<3>) is set, program
execution switches to the external oscillator.
3.6.1
Two-Speed Start-up mode is configured by the
following settings:
• IESO = 1 (CONFIG<10>) Internal/External Switch
• SCS = 0.
• FOSC configured for LP, XT or HS mode.
Two-Speed Start-up mode is entered after:
• Power-on Reset (POR) and, if enabled, after
• Wake-up from Sleep.
If the external clock oscillator is configured to be anything
other than LP, XT or HS mode, then Two-Speed Start-up
is disabled. This is because the external clock oscillator
does not require any stabilization time after POR or an
exit from Sleep.
DS41250B-page 40
Note:
Over bit.
PWRT has expired, or
Section 3.3.1
Two-Speed Clock Start-up Mode
OSCILLATOR START-UP TIME-OUT
STATUS BIT
Executing a SLEEP instruction will abort
the oscillator start-up time and will cause
the OSTS bit (OSCCON<3>) to remain
clear.
TWO-SPEED START-UP MODE
CONFIGURATION
until
1024
“Oscillator
oscillations
Start-up
are
counted.
Timer
Preliminary
3.6.2
1.
2.
3.
4.
5.
6.
7.
3.6.3
Checking the state of the OSTS bit (OSCCON<3>) will
confirm if the PIC16F91X is running from the external
clock source as defined by the FOSC bits in the
Configuration Word (CONFIG) or the internal oscillator.
Wake-up from Power-on Reset or Sleep.
Instructions begin execution by the internal
oscillator at the frequency set in the IRCF bits
(OSCCON<6:4>).
OST enabled to count 1024 clock cycles.
OST timed out, wait for falling edge of the
internal oscillator.
OSTS is set.
System clock held low until the next falling edge
of new clock (LP, XT or HS mode).
System clock is switched to external clock
source.
TWO-SPEED START-UP
SEQUENCE
CHECKING EXTERNAL/INTERNAL
CLOCK STATUS
 2004 Microchip Technology Inc.